The fields lie in a part of the Mediterranean that is claimed by Israel for gas exploration and production, but Lebanon says the fields lie within its territorial waters.

"The decision to deploy drones was made in order to maintain a 24-hour presence over the site," the paper said, adding that the air force was equipped with the locally made Heron drone, which has special electro-optics designed for maritime work.

The Israeli military would not confirm or deny the Post report to AFP.

The paper said that the air force started aerial surveillance after a warning last month from Hezbollah.

"The Israeli enemy cannot drill a single metre in these waters to search for gas and oil if the zone is disputed... No company can carry out prospecting work in waters whose sovereignty is contested," the Shiite group said.

The Hezbollah threat came after Israel's cabinet approved a map of the country's proposed maritime borders with Lebanon and submitted it to the United Nations, which has been asked to mediate in the dispute.

The map conflicts with one submitted by Lebanon to the UN last year, which gives Israel less territory.

The two countries are technically at war and will not negotiate face to face.